1. Field of the Invention
The present invention relates to a blade member, a cleaner and an image forming apparatus, and more particularly relates to a blade member in contact with a surface of a photoreceptor, a cleaner, and an image forming apparatus.
2. Description of Related Art
As a conventional blade member used in an image forming apparatus, there is for example known a cleaning blade described in Japanese Patent Laid-Open Publication No. 2010-66333. The cleaning blade has a backup layer and an edge portion. The backup layer and the edge portion are made up of a polyurethane elastic material. The edge portion is in contact with a photoreceptor to clean the surface of the photoreceptor, and is provided at the tip of the backup layer.
Further, in the cleaning blade described in Japanese Patent Laid-Open Publication No. 2010-66333, the JIS-A hardness of the backup layer is set lower than the JIS-A hardness of the edge portion. By setting the hardness of the edge portion to relatively high hardness as thus described, abrasion resistance and cleaning performance of the edge portion are sought to be improved. Further, by setting the hardness of the backup layer to relatively low hardness, occurrence of eternal distortion in the backup layer is suppressed.
However, the cleaning blade described in Japanese Patent Laid-Open Publication No. 2010-66333 does not sufficiently suppress abrasion that occurs in the edge portion, as described below. The edge portion and the backup layer have different loss tangents (tan δ). When the loss tangent of the edge portion and the loss tangent of the backup layer are different, a vibration that is generated by the contact of the edge portion with the surface of the photoreceptor is reflected on a boundary between the edge portion and the backup layer. Accordingly, a stationary wave is generated in the edge portion due to the vibration generated between the edge portion and the surface of the photoreceptor and the vibration reflected on the boundary between the edge portion and the backup layer. Therefore, in addition to a stick-slip vibration which is normally generated by a slide of the edge portion sliding on the surface of the photoreceptor, a micro vibration is generated in the edge portion due to the stationary wave, thus leading to large development in abrasion of the contact layer.